CALGARY -- Two Alberta girls have been located and are safe after they were allegedly abducted by their mother.

Hours after Mounties issued an Amber Alert for the girls, age 6 and 12, they were found at the Anderson Creek Campground in Boston Bar, B.C., unharmed. Their 48-year-old mother was taken into custody and charged with two counts of abduction.

The children went missing Monday morning after being picked up at their school in the tiny hamlet of Brant, near Vulcan, some 130 km southeast of Calgary.

Two days after the alleged abduction, Mounties issued an Amber Alert over growing concerns the girls were in grave danger.

Insp. Tony Hamori, who heads RCMP major crimes in southern Alberta, said information came to light over the last 24 to 48 hours to elevate concern for the girls.

“We’re aware (the mother) was very frustrated and angry and we feel that might lead to erratic behaviour on her part,” he said, shortly before it became clear the girls had been found.

“She made certain statements to people - indicating that this situation could become fairly desperate for her,” he said.

“It was very reasonable to assume that harm could come to the children if action wasn’t taken quickly.”

Asked if police believed they were facing a potential murder-suicide scenario, Hamori said “more to the effect that she wanted her children and didn’t want anyone else to have them - extrapolate from that what you will.”

Hamori said the mother was angered by a custody order earlier this year.

Court documents obtained by CTV suggest her mental state had recently begun to deteriorate, leading her family to have her committed to a psychiatric hospital.

According to the documents, she was charged with “intent to cause bodily harm with kitchen knives” by setting a trap, mischief to property as well as 24 counts of attempting to acquire prescription drugs with forged documents.

Online ramblings about the devil and demons left family members worried about her ability to properly care for her children, the documents suggest.

Child welfare intervened three times since 2008, the documents state, investigating the use of “corporal punishment on kids.”

Boston Bar sits along the Trans-Canada Hwy., about 60 km north of Hope and some 500 km southwest of Golden.

Hamori said the mother has been taken to the RCMP detachment in Hope, B.C., where she’ll be processed and then returned to Alberta to face two charges of abduction contrary to court order.

The children are in the custody of B.C.'s child and family services and waiting to be reunited with other members of their family.